Three Runs, No Rival Runners: Symbiosis Gives Marathon a Permanent PvE Mode

A trip to Tau Ceti IV usually comes with a question: who else is out there looking for the same loot? In Expedition, the answer is no rival Runners. The mode debuts on December 8, 2026, as part of Marathon: Symbiosis, giving solo players and crews a permanent way to explore the colony and tackle its hazards in PvE. The gameplay trailer also introduces the BISHOP Runner shell, a 3v3 Deathmatch beta, and a version of Perimeter transformed by fungal growth.

Expedition Builds Its PvE Challenge Across Three Runs

The first phase of Expedition is built around a three-run series. You can go in alone or bring a crew, with combat and environmental challenges providing the pressure that normally comes from sharing a map with rival players. Flash Boosts let you shape your build during a run, so the choices you make after deployment are part of how you take on the series.

Bungie describes this as the first phase of Marathon’s first permanent PvE experience. The distinction matters for players who tried limited-time experiments such as Vault Breaker: Expedition is intended to give them an ongoing place to explore, pursue loot, and work towards tougher PvE challenges at their own pace. Bungie’s roadmap puts further work on connecting PvE, PvP, and mixed extraction play in March, so December is the first step in that plan.

Deathmatch Puts Two Crews on the Clock

For players who want a fight without an extraction run attached, Deathmatch (Beta) puts two teams of three into short matches where they compete for points. Your permanent loadout is safe, which makes the beta a place to try unfamiliar equipment or practise fighting another crew without putting your regular gear on the line. Bungie is introducing the mode as an experiment, while Expedition is planned as a permanent addition.

There is also a place to test equipment before queuing for either kind of fight. Limbo is a new social space with firing ranges and a duelling pit. The range lets you get familiar with a weapon on your own, while the pit gives you a chance to see how it feels against another Runner.

BISHOP Brings a Blade to a Colony Full of Guns

BISHOP is designed around speed, surprise, and short bursts of melee damage. Bungie describes a fast, surgical fighter: a shell for players who want to close the distance quickly and make the most of the opening they find. That gives BISHOP a clear identity even before players get to try its full kit.

The update’s two new firearms give players different reasons to visit Limbo’s range. The V17 Flamethrower is built for short-range area denial, while the Maverick introduces a revolver archetype with the feel of a hand cannon. One is meant to make a nearby stretch of ground difficult to cross; the other gives players a new sidearm to get familiar with.

Perimeter Opens Up Below the Surface

Fungal growth and alien life have changed Perimeter, opening routes into the underground Burrows and the submerged Reservoir. The Tick Queen lurks deeper below. Bungie has also described the expanded zone as a place to take on challenges and pursue rare rewards comparable to those found in areas such as Pinwheel in Outpost and the Upper Complex on Night Marsh. For crews that already know the way across Perimeter, the update gives them a reason to look below it.

Play for Free from December 8 to 15

Open Play Week runs from December 8 to 15 and gives players access to the full game, including the Symbiosis additions. If you buy Marathon after the trial, your unlocked items and progression carry over.

The Crew Up event runs through December 22. To enter, redeem DMA-T7Y-XJL on Bungie.net once Symbiosis goes live, then check the Events section of the in-game Codex. Although Expedition supports solo play, these challenges require at least one other crew member who has also redeemed the code. Each player can earn their own rewards, including the Queen’s Nest emblem, Arata Vectus Destroyer skin, and Exterminator title. If your crew is joining for free, December 15 is the deadline to play together without buying the game; after that, Crew Up continues for owners through December 22.